Re: [xml] Attributes without knowing name

[Daniel Veillard <veillard redhat com>]

On Fri, Feb 01, 2002 at 01:18:50PM +0100, Rygg Christian Ingemann wrote:
> I'm working on an XML cryptographic signer, both in Java and in C++. The
> Java version (Using Xerces) is finished, but I have now hit a problem in the
> C++ version (Using libxml).
>
> When signing, the string that is signed must be identical to the one which
> is checked at some later time. The problem with this and XML is that
> attribute order isn't important, and libxml and Xerces orders them
> diffrently, so I need to sort them. The signer must be general, so it
> shouldn't need to know the names of the attributes in the given element. So,
> I need to get all the attributes from an element without knowing the names
> of these attributes. I was looking at the documentation, for something like:
>
> xmlGetPropCount(xmlNodePtr node);
>
> and
>
> xmlGetProp(xmlNodePtr node, int index);
>
> ... but I couldn't find anything like this, or anything that could do the
> job. Is what I'm attempting possible, and if so, how?

  It's not accessible directly as a function, but directly from the
xmlNodePtr structure (which is not opaque),
    node->properties
   containst the first xmlAttrPtr (or NULL)
    node->properties->next
   containst the second xmlAttrPtr (or NULL)
 etc ...
  the xmlAttrPtr list is a doubly chained list, reordering the elements
should not be a proble if you need to, just make sure all pointers
(node->properties , ->next and ->prev for the attributes) are coherent.

Daniel

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